Guo Meimei in front of an Aston Martin in Beijing, one of many pictures she posted online of her apparently lavish lifestyle. Photograph: AFP

Gazing uncertainly past the camera, she recounted her sins in a soft, hesitant voice. An orange prison jacket had replaced her designer clothing. Though her case might be more salacious than usual, the overall effect was familiar: this was the latest videoed confession aired by China's state broadcaster.

"People who have been confessing on the state broadcaster have not done any serious crimes. We should ask ourselves why their confessions should take up the state broadcaster's precious airtime."

While detainees have been interviewed on television before, their confessions have usually been aired after court cases concluded, he said. Others said such videos had involved regular criminal cases rather than those with a political dimension.

For the party, confessions are not only about proving the case against the suspect, but also reforming the individual's thought and setting an example to others. "These are model performances meant to publicly abase high-profile figures, demonstrate their submission to party and state authority, communicate new standards of behaviour and warn others to conform, and reclaim popular legitimacy," said Tiffert. He drew a comparison with the pre-trial publication of confessions in newspapers in earlier anti-corruption drives such as the 1951 "three-anti" campaign.

Guo's cowed demeanour was in striking contrast with her reputation for flaunting designer wares and bragging about her wealth. She had parlayed an internet scandal into minor celebrity, having initially gaining notoriety for posting pictures of herself living lavishly while falsely claiming she was a senior figure with the Chinese Red Cross. Donations to the charity plummeted because people saw her as evidence of wrongdoing. "Because of my own vanity, I made a huge mistake," she said of that incident.

Chen Li, of the political and judiciary commission, said: "Guo Meimei is a representative for many social problems … Her sugar daddy, showing off her wealth, charity problems, gambling and prostitution are all very serious social issues. We should really think about those issues reflected by Guo Meimei."

Though the titillating details of her case drew plenty of attention, they did not prevent scepticism. Some viewers suggested the authorities were using Guo to divert attention from news stories including the fatal explosion at a factory the previous day that claimed more than 70 lives.

Whether agreeing to record confessions has won suspects more lenient treatment is unclear. Some have subsequently been released, but others are still being held months later or face trial.

A lawyer, Zhou Ze, said his journalist client, Liu Hu, had a simple reason for refusing to record a confession: "He did not believe he was guilty." Liu was released on bail early this month, having been held for a year on suspicion of defamation after accusing a senior official of neglecting his duties.

Zhou said the televised statements were demeaning to individual dignity as well as raising concerns about due process.

"If it is the media [that] decides to publicise televised confessions before a proper trial, it is a violation of media ethics. If the authorities are behind these confessions, it is a severe violation of the basic principle of presumption of innocence," he added.